1 /* $NetBSD: humanize_number.c,v 1.14 2008/04/28 20:22:59 martin Exp $ */ 2 3 /* 4 * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center, by Luke Mewburn and by Tomas Svensson. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include <sys/types.h> 37 #include <assert.h> 38 #include <inttypes.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <locale.h> 43 #include <libutil.h> 44 45 static const int maxscale = 7; 46 47 int 48 humanize_number(char *buf, size_t len, int64_t quotient, 49 const char *suffix, int scale, int flags) 50 { 51 const char *prefixes, *sep; 52 int i, r, remainder, s1, s2, sign; 53 int64_t divisor, max; 54 size_t baselen; 55 56 assert(buf != NULL); 57 assert(suffix != NULL); 58 assert(scale >= 0); 59 assert(scale < maxscale || (((scale & (HN_AUTOSCALE | HN_GETSCALE)) != 0))); 60 assert(!((flags & HN_DIVISOR_1000) && (flags & HN_IEC_PREFIXES))); 61 62 remainder = 0; 63 64 if (flags & HN_IEC_PREFIXES) { 65 baselen = 2; 66 /* 67 * Use the prefixes for power of two recommended by 68 * the International Electrotechnical Commission 69 * (IEC) in IEC 80000-3 (i.e. Ki, Mi, Gi...). 70 * 71 * HN_IEC_PREFIXES implies a divisor of 1024 here 72 * (use of HN_DIVISOR_1000 would have triggered 73 * an assertion earlier). 74 */ 75 divisor = 1024; 76 if (flags & HN_B) 77 prefixes = "B\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei"; 78 else 79 prefixes = "\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei"; 80 } else { 81 baselen = 1; 82 if (flags & HN_DIVISOR_1000) 83 divisor = 1000; 84 else 85 divisor = 1024; 86 87 if (flags & HN_B) 88 prefixes = "B\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E"; 89 else 90 prefixes = "\0\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E"; 91 } 92 93 #define SCALE2PREFIX(scale) (&prefixes[(scale) * 3]) 94 95 if (scale < 0 || (scale >= maxscale && 96 (scale & (HN_AUTOSCALE | HN_GETSCALE)) == 0)) 97 return (-1); 98 99 if (buf == NULL || suffix == NULL) 100 return (-1); 101 102 if (len > 0) 103 buf[0] = '\0'; 104 if (quotient < 0) { 105 sign = -1; 106 quotient = -quotient; 107 baselen += 2; /* sign, digit */ 108 } else { 109 sign = 1; 110 baselen += 1; /* digit */ 111 } 112 if (flags & HN_NOSPACE) 113 sep = ""; 114 else { 115 sep = " "; 116 baselen++; 117 } 118 baselen += strlen(suffix); 119 120 /* Check if enough room for `x y' + suffix + `\0' */ 121 if (len < baselen + 1) 122 return (-1); 123 124 if (scale & (HN_AUTOSCALE | HN_GETSCALE)) { 125 /* See if there is additional columns can be used. */ 126 for (max = 1, i = len - baselen; i-- > 0;) 127 max *= 10; 128 129 /* 130 * Divide the number until it fits the given column. 131 * If there will be an overflow by the rounding below, 132 * divide once more. 133 */ 134 for (i = 0; 135 (quotient >= max || (quotient == max - 1 && remainder >= 950)) && 136 i < maxscale; i++) { 137 remainder = quotient % divisor; 138 quotient /= divisor; 139 } 140 141 if (scale & HN_GETSCALE) 142 return (i); 143 } else { 144 for (i = 0; i < scale && i < maxscale; i++) { 145 remainder = quotient % divisor; 146 quotient /= divisor; 147 } 148 } 149 150 /* If a value <= 9.9 after rounding and ... */ 151 if (quotient <= 9 && remainder < 950 && i > 0 && flags & HN_DECIMAL) { 152 /* baselen + \0 + .N */ 153 if (len < baselen + 1 + 2) 154 return (-1); 155 s1 = (int)quotient + ((remainder + 50) / 1000); 156 s2 = ((remainder + 50) / 100) % 10; 157 r = snprintf(buf, len, "%d%s%d%s%s%s", 158 sign * s1, localeconv()->decimal_point, s2, 159 sep, SCALE2PREFIX(i), suffix); 160 } else 161 r = snprintf(buf, len, "%" PRId64 "%s%s%s", 162 sign * (quotient + (remainder + 50) / 1000), 163 sep, SCALE2PREFIX(i), suffix); 164 165 return (r); 166 } 167 168